Leveling device

ABSTRACT

A device for leveling an object on uneven or sloping floors. The device is comprised of a housing with a substantially hollow portion having a worm gear, a driven gear, and an elevation shaft with threads on at least a portion of the shaft&#39;s external surface. The worm gear operably engages the driven gear, which in turn operably engages the elevation shaft. When the worm gear is rotated in opposite directions, concomitant rotations of the driven gear cause the elevation shaft to move axially up or down, thereby providing leveling motions to an object to which the device is attached. A pad may be attached to one end of the elevation to prevent scratching the surface on which the object rests. The hollow portion of the housing is configured to provide at least one load-bearing surface such that no separate bearings are required with the device.

FIELD OF THE INVENTION

[0001] The present invention generally relates to a leveling device, andmore particularly to an improved device for leveling objects that reston a floor or other substantially horizontal, but yet uneven or slopingsurface.

BACKGROUND OF THE INVENTION

[0002] The need to install and level objects on uneven or sloping floorshas presented a long-standing problem, especially for various types ofapparatuses including machines and appliances. Often floors are notplumb or perfectly flat, yet it is important that all the legs of anobject contact the floor to provide adequate support and to equallydistribute the weight of the object. If all the legs do not contact thefloor, many problems can develop. For example, the outer cabinet andframe of an apparatus may become distorted over time due to nonuniformweight support, thereby impairing the proper operation of the apparatus.For example, this is especially true of refrigeration units, freezers,and ice machines which rely on a level installation to achieve propersealing of their door gaskets. In the case of a motorized apparatus suchas a washing machine, inadequate contact of all its legs with the flooris especially problematic because these devices have a tendency tovibrate and “walk” across the floor if the floor is not level. Annoying“rocking” problems with an apparatus may also result where the legs donot all contact the floor. Moreover, installations that are not levelmay be aesthetically undesirable by the inability to match the heightsof adjacent cabinets, other equipment, or work surfaces.

[0003] Installers and manufacturers have attempted to resolve theleveling problem by developing approaches to compensate for uneven andsloping floors. Where the height of apparatus legs is not adjustable,for example, one such approach used by installers has been to placeshims or wedges made of a suitable material under the legs. Obviously,this technique has numerous drawbacks. First, the apparatus must bemanually lifted while such shims are placed under the legs, therebyoften requiring more than one installer. This situation also increasesthe potential risk of back or other physical injuries to the installers.Second, the shims are not permanently mounted to the apparatus legs andmay shift over time or become completely dislodged. This is especiallyproblematic with motorized apparatuses which vibrate and “walk” asdescribed above.

[0004] Manufacturers have attempted to resolve the leveling problem withnumerous design approaches. One technique which has been employed is toprovide manually adjustable legs or supports, often referred tocommercially as glides or levelers, under each corner of the apparatus'souter cabinet. This consists primarily of a threaded vertical rod whichon one end is screwed into a female threaded coupling near theapparatus's corners. The rod typically has a pad or flattened base ofsome sort disposed on the opposite end which contacts the floor. The padmay also swivel or tilt relative to the longitudinal axis of thevertical rod. These manually adjustable supports, however, are stillplagued by many of the problems encountered with the shim techniquedescribed above. For example, in many cases, the apparatus must belifted manually to unload weight from the legs in order to rotate themand adjust their height. Furthermore, there is usually no way to accessthe rear legs for adjustment once the apparatus is slid into its finalposition because access is often not available from the rear or sides ofthe apparatus. This is particularly true of kitchen appliances such asrefrigerators and dishwashers which are usually placed against a wall inthe rear and have other equipment, cabinets, or a wall positionedagainst one or both sides of the apparatus. The manually adjustable legdesign is also cumbersome to use, involving a time consuming trial anderror approach to leveling the apparatus on uneven floors. The apparatusmust often be slid into and out of its final position numerous timeswhile gradual adjustments are made to the otherwise inaccessible rearsupport legs in hopes of finding the proper height of each rear leg.

[0005] Other approaches have been used with limited success in anattempt to overcome the many problems of leveling objects on unevenfloors. For example, U.S. Pat. No. 4,518,142 to Sulcek et al. disclosesa leveling system for appliances utilizing manually adjustable wheels orrollers for rear supports. Even though the appliance may be easier topush into its final position, the height of the rear supports must beadjusted before the appliance is slid into place, often without accessto the final resting position of the rear supports on the floor. U.S.Pat. No. 5,749,550 to Jackson discloses a rear leveling system forrefrigerators using rollers for rear supports. Although the rearsupports are adjustable from the front of the appliance, the mechanismis complicated and requires virtually all parts to be fabricated frommetal. Like many similar mechanisms, the manufacturing costs are highand they are prone to problems due to their complex design.

[0006] Accordingly, there is a need for a leveling device that is simplein design, economical to produce, and allows adjustment of the height ofthe rear supports or legs after the object is in place.

BRIEF SUMMARY OF THE INVENTION

[0007] The invention is generally directed to an adjustable levelingdevice which can be used for any object, including various apparatusessuch as equipment and appliances.

[0008] In accordance with one embodiment, the leveling device iscomprised of a housing having a base portion, a top portion, and asubstantially hollow portion disposed between the base and top portions.The hollow portion is adapted and configured to provide at least oneload-bearing surface. In one embodiment, the housing may be fabricatedby machining. In another embodiment, the housing may be made of plasticwhich in one embodiment is fabricated by molding.

[0009] The leveling device further comprises an elevation shaft having alongitudinal axis which may be disposed at least partially within thehollow portion and may have threads on at least a portion of itsexternal surface. A means for restraining the elevation shaft fromrotating relative to the housing may also be provided. In oneembodiment, the elevation shaft restraining means comprises an openingdisposed in the top portion of the housing through which the elevationshaft extends, the opening having a flat surface and a flat portion isconfigured on the elevation shaft to operably engage the flat surface inthe opening to prevent the shaft from rotating. In another embodiment,the shaft restraining means comprises a slot extending along a portionof the longitudinal axis of the elevation shaft, an opening disposed inthe top portion of the housing through which the elevation shaftextends, and the opening having a key to operably engage the slot toprevent rotation of the shaft. In yet another embodiment, the shaftrestraining means comprises a key extending along a portion of thelongitudinal axis of the shaft, an opening disposed in the top portionof the housing through which the shaft extends, and the opening having aslot to operably engage the key to prevent rotation of the shaft.

[0010] In accordance with one embodiment, the elevation shaft is axiallymovable to allow at least one end of the shaft to be completelyretracted into the housing.

[0011] The leveling device further comprises a worm gear which may bedisposed within the hollow portion of the housing. The worm gear hasteeth and at least one end of the worm gear may have an extensionprotruding out from the housing which may be configured to facilitaterotation of the worm gear. The extension may be configured to receive atool to rotate the worm gear, which in one embodiment may be a hex head.In accordance with one embodiment of the leveling device, the worm gearis made of plastic.

[0012] The leveling device further comprises a driven gear which mayhave internal threads that are engaged with the threads of the elevationshaft and external teeth that are engaged with the teeth of the wormgear. The driven gear is adapted and configured to operably engage theat least one load-bearing surface of the hollow portion of the housingsuch that no separate bearings are required with the leveling device.

[0013] In one embodiment, the driven gear may be a spur gear. However,in another embodiment, the driven gear may be a helical gear. The drivengear may also include a stem. In accordance with one embodiment, thedriven gear may be made of plastic.

[0014] When the worm gear is rotated in opposite directions, concomitantrotations of the driven gear cause the elevation shaft to move axiallyup or down to provide leveling motions to an object attached to theleveling device.

[0015] The device further comprises a means for retaining the drivengear within the hollow portion of the housing. In one embodiment, themeans for retaining the driven gear within the substantially hollowportion of the housing may be a collar that is fastened within anopening in the base portion. In another embodiment, the driven gearretaining means may be a load-bearing block that is fastened within anopening in the base portion; the block having a hole configured andadapted to receive the elevation shaft.

[0016] In accordance with one embodiment of the leveling device, a meansmay be connected to one end of the elevation shaft for protecting anonuniform surface from damage by contact of the end of the shaft withthe surface. In one embodiment, the surface protecting means maycomprise a pad shaped as a round disk. In one embodiment, the elevationshaft is axially movable such that the pad may be completely retractedinto the housing of the leveling device. In another embodiment, the padmay be rotably connected to the end of the elevation shaft to permitindependent relative rotation between the pad and the shaft. The pad inyet another embodiment may be movably attached to the end of theelevation shaft to permit the pad to tilt at an angle relative to aplane perpendicular to the longitudinal axis of the shaft. In oneembodiment, the angle may range from 0 to about 5 degrees.

[0017] In accordance with another embodiment of the leveling device, thesurface protecting means may comprise a roller. In one embodiment, theroller may be pivotally mounted to the end of the elevation shaft topermit swiveling of the roller around the elevation shaft.

[0018] In accordance with one embodiment of the leveling device, thehousing is adapted and configured to attach to an object. The topportion of the housing may be situated opposite the base portion of thehousing, and each such portion may have at least one opening. The hollowportion of the housing may further comprise a first internal compartmentwith a first cross-sectional area parallel to the base portion and asecond internal compartment with a second cross-sectional area parallelto the base portion. The second cross-sectional area may be smaller thanthe first cross-sectional area. The first internal compartmentcommunicates with the second internal compartment and the at least oneopening in the base portion. The second internal compartmentcommunicates with the at least one opening in the top portion of thehousing. A stepped transition may be provided between the first andsecond internal compartment which is adapted and configured to define atleast one load-bearing surface. In one embodiment, the driven gear mayhave a top and bottom wherein the top contacts the load-bearing surfaceof the stepped transition without any separate bearings.

[0019] In accordance with one embodiment of the leveling device, thedriven gear may be disposed in the first internal compartment of thehousing. A stem may also be provided in another embodiment extendingfrom the top of the driven gear, wherein the stem may be disposed in thesecond internal compartment of the housing.

[0020] In accordance with another embodiment of the housing of theleveling device, the hollow portion may define a gear cavity having afirst cross-sectional area parallel to the base portion of the housing.The hollow portion may further define a gear stem cavity having a secondcross-sectional area parallel to the base portion of the housing whichis smaller than the cross-sectional area of the gear cavity. The gearstem cavity may communicate with the opening in the top portion of thehousing wherein the gear cavity is coaxially aligned with the gear stemcavity and a stepped transition is formed between the gear cavity andthe gear stem cavity; the stepped transition providing a load-bearingsurface.

[0021] In another embodiment of the leveling device, the housing maycomprise a substantially rectangular cavity for the worm gear. The wormgear cavity may have an open top, a closed bottom, two elongated sides,and two ends with an opening disposed in each end. The shape of theclosed bottom may be semi-circular.

[0022] In accordance with one embodiment, the housing of the levelingdevice may be adapted and configured to attach to an object in aninverted position whereby the base portion is oriented upwardly and thetop portion is oriented downwardly. In this embodiment, a load-bearingblock may be inserted within the opening in the base portion of thehousing, the block having a hole configured and adapted to receive theelevation shaft, thereby providing a load-bearing surface for support ofthe load imposed on the leveling device by the object.

[0023] A method for leveling an object is also provided which maycomprise the steps of:

[0024] (a) providing at least two leveling devices each comprising:

[0025] a housing having a base portion, a top portion, and asubstantially hollow portion;

[0026] an elevation shaft having a longitudinal axis disposed at leastpartially within the hollow portion, at least a portion of the shafthaving threads on its external surface;

[0027] a worm gear having teeth disposed within the housing, at leastone end of the worm gear having an extension protruding out from thehousing and configured to receive a tool to facilitate rotation of theworm gear;

[0028] a driven gear disposed within the hollow portion having internalthreads engaged with the threads of the elevation shaft and externalgear teeth engaged with the teeth of the worm gear;

[0029] means for retaining the driven gear within the hollow portion;and

[0030] means for restraining the elevation shaft from rotating relativeto the housing,

[0031] whereby upon rotation of the worm gear in opposite directions andconcomitant rotations of the driven gear, the elevation shaft is causedto move axially up or down;

[0032] (b) providing a tool configured to operably engage the at leastone end of the worm gear extending out from the housing;

[0033] (c) providing an object to which the at least two levelingdevices are mounted, the object providing access for the tool to engagethe at least two leveling devices;

[0034] (d) engaging the tool with the extension of the at least one endof the worm gear protruding out from the housing of one of the at leasttwo leveling devices; and

[0035] (e) rotating the worm gear of one of the at least two levelingdevices with the tool to raise or lower the object.

[0036] In one embodiment, the method for leveling an object describedabove comprises rotating the worm gear of at least one of the levelingdevices to level an object. In another embodiment, the method forleveling an object described above comprises rotating the worm gear ofboth leveling devices to level object. In accordance with oneembodiment, an appliance is the object to be leveled by the methoddescribed above.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The features and advantages of the present invention will becomemore readily apparent from the following detailed description of theinvention in which like elements are labeled similarly and in which:

[0038]FIG. 1A is a top plan view of one embodiment of the levelingdevice of the present invention in which the worm gear is visible andfurther shown with the housing partially cut away to reveal the drivengear;

[0039]FIG. 1B is a side view of the leveling device of FIG. 1A which hasa pad disposed on one end of the elevation shaft and is shown with thehousing and collar partially cut away to reveal the elevation shaft,driven gear, and worm gear;

[0040]FIG. 1C is a top plan view of another embodiment of the levelingdevice of the present invention in which the worm gear is visible andfurther shown with the housing partially cut away to reveal the drivengear;

[0041]FIG. 1D is a top plan view of another embodiment of the levelingdevice of the present invention in which the worm gear is visible andfurther shown with the housing partially cut away to reveal the drivengear;

[0042]FIG. 2A is a top plan view of the housing of the leveling deviceof FIG. 1;

[0043]FIG. 2B is a cross-sectional view of the housing of the levelingdevice of FIG. 2A taken through line 2B-2B in FIG. 2A;

[0044]FIG. 3A is a side view of the driven gear of the leveling deviceof FIG. 1 which has a single stem;

[0045]FIG. 3B is an end view of the driven gear of FIG. 3A of theleveling device of FIG. 1 viewed from the end opposite the single stem;

[0046]FIG. 3C is a side view of another embodiment of the driven gear ofthe leveling device of FIG. 1 which has two stems which may be used withthe invention;

[0047]FIG. 4A is a side view of the worm gear of the leveling device ofFIG. 1;

[0048]FIG. 4B is an end view of the worm gear of FIG. 4A of the levelingdevice of FIG. 1;

[0049]FIG. 4C is a side view of the extension rod which may be used withthe worm gear of FIG. 4A;

[0050]FIG. 5A is a side view of the elevation shaft of the levelingdevice of FIG. 1 which depicts an end configuration adapted to receive apad;

[0051]FIG. 5B is an end view of the elevation shaft of FIG. 5A of theleveling device of FIG. 1 viewed from the end adapted to receive a pad;

[0052]FIG. 5C is an end view of the elevation shaft of FIG. 5A of theleveling device of FIG. 1 viewed from the end opposite FIG. 5B;

[0053]FIG. 5D is an end view of an optional elevation shaft of FIG. 5Aof the leveling device of FIG. 1 viewed from the end opposite FIG. 5B;

[0054]FIG. 5E is an end view of another optional elevation shaft of FIG.5A of the leveling device of FIG. 1 viewed from the end opposite FIG.5B;

[0055]FIG. 6A is side view of the driven gear retaining collar of theleveling device of FIG. 1;

[0056]FIG. 6B is an end view of the driven gear retaining collar of FIG.6A of the leveling device of FIG. 1;

[0057]FIG. 7A is a side view of the load-bearing driven gear retainer ofthe leveling device of FIG. 1 which may be used in lieu of a collar whenthe leveling device is installed vertically inverted by 180 degrees;

[0058]FIG. 7B is an end view of the load-bearing driven gear retainer ofFIG. 7A of the leveling device of FIG. 1 which may be used in lieu of acollar when the leveling device is installed vertically inverted by 180degrees;

[0059]FIG. 8 is a side view of another embodiment of the leveling deviceof the present invention which has a roller disposed at the end of theelevation shaft, and is shown with the housing and collar partially cutaway to reveal the elevation shaft, driven gear, and worm gear in thehousing;

[0060]FIG. 9 is a side view of the leveling device of the presentinvention which has a pad and is shown installed in its normal verticalorientation in an object, wherein the leveling device is further shownwith the housing partially cut away to reveal the elevation shaft,driven gear, and worm gear in the housing;

[0061]FIG. 10 is a side view of the leveling device of the presentinvention which has a pad and is shown installed vertically inverted by180 degrees from its normal vertical orientation in an object, whereinthe leveling device is further shown with the housing and load-bearingretaining block partially cut away to reveal the elevation shaft, drivengear, and internal compartments of the housing; and

[0062]FIG. 11 is a top view of the base and bottom frame of an applianceshowing the leveling device of the present invention installed near bothrear corners of the appliance with the worm gear extension rods routedto the front of the appliance.

DETAILED DESCRIPTION OF THE INVENTION

[0063] A first embodiment of the leveling device 1 is shown in FIGS. 1A& B as generally including a housing 2, a worm gear 25, a driven gear 14having internal threads 61, and a threaded elevation shaft 21. Aretaining collar 28 may be provided which holds the driven gear 14inside the housing 2. A pad 30 may also be disposed on the lower end ofthe elevation shaft as shown. Leveling devices such as the presentinvention are installed on the bottom of an object, such as an appliancefor example, where they function as a leg or support that may beadjusted to level the object when installed on a nonuniform surface.Basically, the leveling device 1 operates by rotating the worm gear 25which causes concomitant rotations of the driven gear 14. The internalthreads of the rotating driven gear 14 engage the threads of theelevation shaft 21. Since means are provided to prevent or restrain theshaft 21 from rotating in relation to the housing 2 (describedhereafter), rotation of the driven gear 14 is translated into only anaxial up or down motion of the shaft by the threaded connection betweenthese two components. Depending on the direction in which the drivengear 14 is rotated, this causes the elevation shaft to be raised orlowered, thereby imparting the same, but opposite leveling motions tothe object attached to the leveling device 1 (i.e., lowering theelevation shaft raises the object, and vice-versa).

[0064] It should be noted that the leveling device 1 of the inventiondoes not require any separate load-carrying bearings, which arenoticeably absent in FIG. 1B. The absence of separate bearings allowsfor design simplicity, flexibility in the selection of materials forcomponents, and a leveling device 1 which is easy and economical tomanufacture.

[0065] The components and operation of the leveling device 1 aredescribed in greater detail hereafter by reference to the drawings. Adetailed description of the housing 2 will be provided first, followedby discussion of the remaining components of the leveling device 1.

[0066] Referring now to FIGS. 2A & B, the housing 2 may have a baseportion 3, a top portion 13, and a substantially hollow portion 4. Thehousing 2 may be made from any suitable material that possessessufficient structural strength to withstand any static and dynamic loadsthat may imposed on the leveling device 1 by the object to which it isattached.

[0067] Preferably, the housing is made of a commercially availableplastic of suitable strength such as, but not limited to, polycarbonate,polyvinyl chloride, etc. However, the housing 2 may also be made frommetal, fiberglass, etc. It will be appreciated that material selectionfor the housing 2 is a matter of design choice and economics, andtherefore the housing material is expressly not limited to the preferredembodiment disclosed herein.

[0068] The housing 2 may be a one-piece construction which is cast ormolded in a single piece, machined from a single piece of materialstock, or fabricated by any other suitable manner commonly known in theart. Alternatively, the housing 2 may made of two or more pieces thatare joined together either in a permanent type of assembly (e.g., weldedor soldered metal connections, glued or heat fused plastic connections,riveted or pinned connections, etc.) or semi-permanent type of assembly(e.g., threaded, screwed, or keyed connections, etc. ) which can bereadily disassembled. Of course, a combination of permanent andsemi-permanent types of fabrication may also be employed.

[0069] As shown in FIGS. 1A & B, the base portion 3 is a substantiallyflat, planar surface which is typically attached to the underside of anobject. The base portion 3 may be provided with holes 11 as shown (FIG.2A) for attaching the leveling device 1 to an object. The size, numberof holes, and their physical layout on the base portion 3 will bedependent upon the particular intended application, and therefore thebase is not limited to the embodiment shown and described. The levelingdevice 1 may be attached to the object in any conventional manner knownin the art and commonly used to attach supports or legs. For example,the leveling device 1 may be attached with threaded fasteners (e.g.,bolts, screws, etc.) which are inserted through the holes 11 in the baseportion 3 and engage a threaded female socket provided on the bottom ofthe object cabinet or frame (FIGS. 9 & 10). The method of attaching theleveling device 1 to an object is not limited to the use of holes in thebase portion 3 and threaded fasteners. Depending on the material ofconstruction and configuration of the base portion 3 and the object, theleveling device 1 may be attached to an object by riveting, welding, orany other method commonly known in the art which can provide anattachment.

[0070] It will be readily appreciated that the configuration, size, andthickness of the base portion 3 is strictly a matter of design choice,and is dependent upon the intended application and the configuration ofthe object to which the base portion 3 will be attached. Accordingly,the base portion 3 is not limited to the embodiment shown in FIGS. 2A &B.

[0071] As shown in FIG. 2B, the substantially hollow portion 4 of thehousing 2 comprises one or more interconnected internal chambers orcompartments which may be coaxially aligned and different in size. Inone embodiment, a first internal compartment 5 and a second internalcompartment 6 are provided in which the compartments have differentcross-sectional areas when viewed from the base portion 3. Preferably,compartments 5 and 6 have circular cross-sections (best seen in FIG. 2A)with the cross-section of compartment 5 being larger than that ofcompartment 6. This arrangement may be used where a driven gear 14 witha single stem 16 (FIG. 3A) is used in the leveling device 1. In thiscase, the driven gear 14 would occupy a portion of the space of thefirst compartment 5, while the stem 16 would occupy the secondcompartment 6 (see FIG. 1B).

[0072] The configuration and size of compartments 5 and 6 are adapted tocorrespond with the configuration and size of the driven gear 14 and itsstem 16, respectively. The first compartment 5 has a side wall 74 and anupper horizontal surface 70. Similarly, the second compartment 6 has aside wall 71 and an upper horizontal surface 73. The side wall 71 of thesecond compartment 6 intersects the upper surface 70 of the firstcompartment 5 at an angle θ as shown in FIG. 2B, thereby allowing bothcompartments 5 & 6 to be in physical communication with one another.Preferably, the angle θ is 90 degrees; however, any angle may be usedwhich is a matter of design choice and dependent upon the configurationof the driven gear 14 and any stems 16 (see FIGS. 3A-E) which may belocated in the housing 2.

[0073] With continuing reference to FIG. 2B, the upper surface 70 of thefirst compartment 5 and side wall 71 of the second compartment define astepped transition 32 which is formed between the first compartment 5and second compartment 6. The stepped transition 32 provides horizontaland vertical load-bearing surfaces which function in concert with thedriven gear 14 and/or any stems 16 (see FIGS. 3A-E) to resist the staticand dynamic loads which may be imposed on the leveling device 1 by anobject to which the leveling device is attached. The upper surface 73 ofthe second compartment 6 may also be designed to provide a load-bearingsurface which functions in concert with the stem 16 of the driven gear14 (see, e.g., FIGS. 3A-E) to resist static and dynamic vertical loadsimposed on the leveling device 1.

[0074] It should be noted that the invention is not limited to a housing2 containing two internal compartments as shown in FIGS. 2A & B. Indeed,any number, shape, or arrangement of compartments is possible which is amatter of design choice and dependent upon the intended application ofthe leveling device 1. For example, a single internal compartment may beused where a driven gear 14 without a stem (not shown) is used in theleveling device 1. Alternatively, the housing 2 may have more than twocompartments depending on the arrangement and number of internal gearingassembly components used in the leveling device 1. It should further benoted, as previously mentioned, that the housing and consequently alsoits internal compartment(s) may be formed as either an integral part ofthe housing 2, or by any number of separate pieces or components whichmay be assembled in either a permanent or semi-permanent type fashion.

[0075] As shown in FIG. 2B, a hole 31 is provided in the base portion 3which opens into the first compartment 5 from below, and which ispreferably the same diameter as the first compartment 5. The hole 31allows the driven gear 14 to be inserted in the hollow portion 4, andfurther provides a space in one embodiment of the invention wherein thepad 30 may be completely withdrawn into the housing 2 (FIG. 1B).

[0076] The top portion 13 of housing 2 has at least one hole 9 disposedtherein which is contiguous and axially aligned with the secondcompartment 6 and which penetrates the upper surface 73 of the secondcompartment 6 as shown in FIG. 2B. Hole 9 provides the capability toallow the elevation shaft 21 to pass through the top portion 13 of thehousing 2. As best shown in FIG. 2A, the hole 9 may be provided with aflat surface 12 to prevent the elevation shaft 21 from rotating when itslides through the hole. This causes the internal threads of the drivengear 14 (FIGS. 3A-E) to engage the threads on the elevation shaft 21(FIG. 5A), thereby imparting an axial up or down movement to the shaftas described in additional detail below.

[0077] It will be appreciated that the external shape or geometry ofhousing 2 is a matter of design choice and discretionary being basedupon a number of factors including the intended application,manufacturing considerations for the housing, the configuration of theobject to which the leveling device 1 will be attached, etc.Accordingly, the leveling device 1 is not limited to the shape of thehousing described herein. For example, although the exterior geometry ofthe housing 2 of shown in FIGS. 2A & B is depicted with partiallyrounded sides and a truncated conical top, a square or rectangularshaped exterior, for example, may also be used for the housing.

[0078] With continuing reference to FIGS. 2A & B, a substantiallyrectangular shaped well or cavity 7 may be provided in the housing 2 forthe worm gear 25 (FIG. 4A). The worm gear cavity 7 may have an open topwhich allows access to the worm gear from the top portion 13 of thehousing 2. The bottom half 81 of the cavity 7 may have a semi-circularcross section to match the shape and size of the worm gear 25.Importantly, the cavity 7 opens into and is contiguous with the firstinternal compartment 5 wherein the driven gear 14 (FIG. 3A) is housed.This allows the teeth 27 of the worm gear 25 to contact and mesh withthe teeth 15 of the driven gear 14 when both components are inserted intheir respective positions within the housing 2. It will be readilyappreciated that the size and configuration of the worm gear cavity 7 isa matter of design choice and there are numerous possible designs forsuch a cavity. Accordingly, the design of the worm gear cavity 7 is notlimited to the size and configuration shown.

[0079] The housing 2 may have one or two holes 8 that extend from theoutside through the housing into the worm gear cavity 7 (FIGS. 2A & 2B).The purpose of the hole(s) 8 is twofold. fold. First, the hole(s) 8allow an extension to be provided for one or both ends of the shaft 26of the worm gear 25 (FIG. 4A) which protrude out beyond the housing 2 sothat the worm gear may be turned by applying an external rotationalforce to the shaft. Second, the hole(s) 8 serves to support the ends ofthe worm gear 25. The hole(s) 8 may be provided with a metal shoulderbushing 82 as shown in FIG. 1A; however, no bushing need be provided anda plain hole(s) may be used.

[0080] FIGS. 3A-E depict several embodiments the driven gear 14 whichmay be used and is engaged by the worm gear 25 to raise and lower theelevation shaft 21 of the leveling device 1 (see FIG. 1B). The drivengear 14 may have an upper flat surface 62 and lower flat surface 63. Thedriven gear 14 may be any type of gear which is capable of being engagedby worm gear 25. Preferably, the driven gear 14 is a spur gear as shownand which is readily recognizable by its teeth 15 which are located onthe side of the gear and oriented in a straight pattern perpendicular tothe two flat surfaces 62 and 63 of the gear. However, the invention isexpressly not limited to the use of spur gears, and as mentioned above,any other type of suitable gear such as a helical gear (in which theteeth are oriented at an angle to the flat surfaces of the gear) mayalso be used. In contrast to some of these other types of gears withmore complex teeth patterns, spur gears are simple in design and hencevery economical to produce. Furthermore, since a spur gear has astraight tooth pattern, the spur gear may be used with a worm gear 25having either left or right-handed threads. The practical and economicadvantages of this flexibility will be evident upon further discussionof the leveling device 1 below.

[0081] The driven gear 14 may contain a stem 16 as shown in FIGS. 3A-Dwhich protrudes or extends outward from the upper flat surface 62 of thegear. Optionally, in another embodiment shown in FIG. 3E, a second stem30 may also be provided which protrudes from the lower surface 63 of thegear as shown in FIG. 3C. However, it should be noted that a driven gear14 may also be used which does not have any stems. Preferably, thedriven gear 14 has a single stem 16. Accordingly, it will be appreciatedthat the presence and number of stems, if any, is a matter of designchoice and the number, as well as whether the driven gear 14 has anystem is not limited to the embodiments described herein.

[0082] Although the intersection between the upper flat surface 62 ofthe driven gear 14 and stem 16 is shown in FIGS. 3A, C, & E to be at a90 degree angle, a bevel (e.g., 45 degrees — not shown) may also be usedbetween these two structures to reduce the stress concentration at theintersection. In that embodiment, the stepped transition 32 between thefirst and second internal compartments 5 & 6, respectively, would becooperatively configured to accommodate the bevel (not shown).

[0083] The driven gear 14, and stems 16 and 30 if they are used, arepreferably all made of plastic. However, any suitable material may beused including metals such as stainless steel for example.

[0084] As shown in FIGS. 3A & B, an opening 19 is disposed in the drivengear 14 which runs completely through the centerline of the gear and anystem(s) if provided. The opening forms a passageway configured andadapted to receive the elevation shaft 21 and allows the shaft to moveback and forth through the driven gear 14. Threads 61 are providedwithin the opening 19 which are designed to operably engage the threads60 on the elevation shaft 21 (FIG. 5A).

[0085] Where the elevation shaft 21 is made of metal and the driven gear14 is made of plastic, there would be a possibility of stripping threadson the plastic driven gear if opening 19 were directly threaded toreceive the elevation shaft. This situation may be avoided by theembodiment shown in FIGS. 3C-E wherein a metal bushing 17 containinginternal threads 20 is preferably inserted into and preferably fixedlyattached in opening 19. The bushing threads 20 engage the threads on themetal elevation shaft 21. Since both the bushing 17 and elevation shaft21 are made of the same material, preferably having comparablemechanical strength properties, stripping of the threads on eithercomponent is prevented. Preferably, the bushing 17 and elevation shaft21 are both made of plated or unplated metal, more preferably stainlesssteel.

[0086] It will be appreciated as described above in conjunction withFIGS. 3A & B that if the elevation shaft 21 and driven gear 14 are bothmade of plastic (having comparable mechanical strength properties), nothreaded metal bushing 17 is necessary and the opening 19 may bethreaded directly to receive the elevation shaft 21 without concern forstripping threads on either component.

[0087] The bushing 17 may be inserted directly into the driven gear 14opposite the stem 16 as depicted in FIGS. 3A-D where only a single stemis used or where no stem is used at all (not shown). Alternatively, thebushing 17 may be inserted into the stem. This latter arrangement isnecessary where two stems are provided with the driven gear 14 (see,e.g., FIG. 3E). Preferably, the bushing 17 is held in place by pressfitting the bushing into the driven gear 14, or stems 16 or 17,depending upon the gear and stem configuration selected and thediscretion of the designer. However, the bushing 17 may alternatively beheld in place by any other suitable means commonly known in the art(e.g., adhesives, etc.) which is capable of providing a rigid attachmentsuch that there is no relative rotation between the bushing and thedriven gear 14.

[0088] As best understood with reference to FIGS. 1B & 2B, the preferredembodiment uses a driven gear 14 with a single stem 16 inserted in thesubstantially hollow portion 4 of the leveling device 1. The driven gear14 is positioned in first compartment 5 while the stem 16 is positionedin the smaller second compartment 6. The diameter of the firstcompartment 5 is fabricated and sized such that it is only slightlylarger than the outside diameter of the driven gear 14. Preferably, theresulting gap between the first compartment 5 and the driven gear 14diameters should not be so large such that there is a loose or sloppyfit of the driven gear 14 in the housing 2, while at the same time thegap should not be so small such that the driven gear 14 cannot freelyrotate without binding with the adjacent first compartment 5 side walls.The proper gap can readily be determined and produced by one skilled inthe art based upon the materials selected for the components and methodsof fabrication employed which will determine the concomitantmanufacturing tolerances. Preferably, the gap between the diameters ofthe second compartment 6 and the stem 16 should be sized similarly.

[0089] The worm gear 25 as shown in FIGS. 1A & B is disposed in cavity 7of the housing 2. With reference to FIGS. 4A-C, the worm gear 25comprises a shaft 26 and external threads 27 which are adapted andconfigured to engage the teeth 15 of the driven gear 14 (FIG. 3B). Asocket 34 may be provided in each end of the shaft 26 which isconfigured to receive an extension rod 36 (see also FIG. 1A) that may beof any length desired and is sized to fit through the holes 8 (FIGS. 1A& 2A) of the housing 2 at each end of the worm gear cavity 7. Whenturned by a tool as described below, the extension rod 36 operablyengages and rotates the worm gear 25 to operate the leveling device 1.Since the extension rods 36 also support and maintain alignment of eachend of the worm gear 25 within the housing 2 when the rods are installedthrough the holes 8, the leveling device 1 preferably has an extensionrod inserted in each socket 34. Preferably, at least one extension rod36 of each leveling device 1 has a length sufficient to reach the frontof an object (e.g., appliance, equipment, etc.) to be leveled where itis readily accessible by an installer. Thus, the extension rods 36 allowthe installer to remotely access and rotate the worm gear 25 in order tooperate the leveling device 1. This is advantageous when the levelingdevice 1 is installed in the rear of the object and would otherwise notbe reachable without the extension rod 36. The front of the extensionrod may be supported by a bracket 51 (FIG. 11) or other suitable meansthat may be provided as part of the object 43.

[0090] It should be recognized that where the leveling device 1 isreadily accessible without the use of a long extension rod 36 routed tothe front of the object, short extension rods may alternatively be used.Accordingly, the extension rods 36 can be made whatever length isnecessary to allow the leveling device 1 to be operated and will bedependent upon the particular design and installation requirementsencountered.

[0091] The insertion end 37 of the extension rod 36 which is insertedinto the socket 34 is configured to match the shape and size of thesocket in the end of the worm gear 25. The socket 34 is of a sufficientdepth to securely seat the extension rod in the worm gear 25. In FIGS.4A & B, the preferred embodiment of the socket 34 and insertion end 37are configured to be square in shape. However, any shape of socket 34and insertion end 37 may be used. It will be appreciated that numerousways can be envisioned to operably couple the extension rods 36 to theworm gear 25. For example, in one alternative embodiment rectangularprojections or ears (not shown) may be attached to the insertion end 37by any suitable means commonly known in the art and which are configuredto securely fit into the square socket 34 shown in FIG. 4B. In anotherembodiment, an axially-aligned open passageway (not shown) may beprovided through the entire length of the worm gear 25 which is adaptedand configured to receive a single extension rod 36. The passagewaywould extend completely through the worm gear 25 from end to end suchthat the extension rod 36 would protrude from each end of the gear 25.As an example, the passageway may have a square cross-section like thatshown in FIG. 4B for socket 34 (but extending completely through theworm gear 25) and at least the portion of the extension rod 36 that runsthrough the worm gear may also have a correspondingly shaped squarecross-section to operably engage the gear. Such a design maximizes thecontact surface between the worm gear 25 and extension rod 36, therebyenhancing the strength of the coupling between the two components.

[0092] Referring now to FIG. 4C, the extension rod 36 has a tooling end38 located opposite the insertion end 37. Preferably, the tooling end 38is in the shape of a hex head; however, any shape may be used. Aninstaller can conveniently operate the leveling device 1 by using a tool(e.g., crescent wrench, socket wrench, electric or air drill withsocket, etc.) to engage the tooling end 38 and rotate the extension rod36 and worm gear 25, thereby imparting leveling motions to an objectattached to the leveling device. Although manual operation of theleveling device 1 by an installer has been discussed, the extension rod36 may also be turned by an electric motor that may be provided with theobject 43. It should also be recognized that the extension rod 36 neednot extend all the way to the front of the object 43. A short extensionrod 36 may alternatively be used which can be reached from the front ofthe object by a manual or power tool having a sufficiently long length.Preferably, however, the extension rod 36 reaches the front of theobject 43.

[0093] It should be noted that the design of the gearing for theleveling device 1 of the invention (i.e., gear ratio, pitch, pressureangle, contact ratio, teeth shape and size, etc.) is well within theambit of knowledge of those skilled in the art and will not be expoundedupon herein for the sake of brevity.

[0094] The elevation shaft 21 in one embodiment as shown in FIG. 5A maycomprise a threaded rod. Although only portions of the shaft 21 areshown as having threads 60 in FIG. 5A (for clarity sake only), theextent of the shaft that is to be threaded can be varied. Indeed, theentire length of the shaft 21 may be threaded. The extent and locationof threads provided is a matter of design choice and will be determinedby ensuring the threading is sufficient to operably engage the drivengear throughout the shaft's 21 expected range of axial movement. It willbe recalled that the threaded elevation shaft 21 engages internalthreads 61 that may be provided in the opening 19 of the driven gear, orinternal threads 20 that may be provided in the metal bushing 17 fittedto the driven gear in an alternate embodiment (see FIGS. 3A-E).

[0095] Preferably, the shaft 21 is made of plated or unplated metal,more preferably stainless steel. However, material selection for theshaft 21 is a matter of design choice and not limited to the preferredembodiments. Thus, for example, a plastic elevation shaft may also beused dependent upon the design considerations involved for a particularapplication.

[0096] As shown in FIGS. 5A & C, a flat area 24 is provided on theelevation shaft 21 which mates with the flat surface 12 provided in hole9 in the top portion 13 of the housing 2 (FIG. 2A) to prevent the shaftfrom rotating as it is raised and lowered through the hole by rotationsof the driven gear 14. If the top portion 13 of the housing 2 is made ofplastic and the elevation shaft 21 is metal, the face of the flatsurface 12 in hole 9 may be fitted with a metal insert 44 to protect thesurface 12 from being damaged by the corresponding flat area 24 on theelevation shaft (see FIG. 1A). Although the insert 44 is shown to begenerally U-shaped and preferably comprised of sheet metal, any type ofinsert and manner of attaching it to the flat surface 12 may be used aswill be commonly known in the art.

[0097] It should be recognized that there are numerous ways which can beused to prevent the elevation shaft 21 from rotating in the housing 2,and the invention is not limited to the technique just described. Forexample, a keyed arrangement between the shaft 21 and housing 2 may alsobe used. In one embodiment, the elevation shaft 21 may be provided witha slot 45 (FIG. 5D) extending along a portion of the longitudinal axisof the shaft. The hole 9 may be configured and provided with a key 46which mates with the slot 45 in the shaft 21 (FIG. 1C). The key 46 maybe a separate component, preferably made of metal, which fits in a slot47 in the opening 9 in the top portion 13 of the housing 2 (FIG. 1C) andis attached thereto by any means commonly known in the art (e.g., setscrew). Alternatively, the key may be formed as an integral part of thehousing itself (not shown) in which case the slot 47 in the housing 2 isnot required. In another embodiment, the shaft 21 may have a key 48(FIG. 5E) extending along a portion of its longitudinal axis which fitsin slot 47 in the opening 9 of the housing 2 (FIG. 1D), therebypreventing the shaft from rotating. Numerous variations of the keyedarrangement are possible and the means for preventing the shaft 21 fromrotating is not limited to the embodiments described herein.

[0098] One end of the elevation shaft 21 may be configured to accept apad 30 (FIG. 1B), roller 44 (FIG. 8), or any other similar means toprotect a flooring surface which the elevation shaft 21 would contactwhen the leveling device 1 is in use. It is common practice to provide asurface protector of some sort on the supports or legs of an object(such as an appliance or office machine, for example) to preventscratching or marring the finish of flooring surface. Preferably, asurface protector of some type is disposed on elevation shaft 21, morepreferably a substantially round flat structure or disk such as a pad 30shown in FIG. 1B is used. The pad 30 may be a commercially-availablebase used for levelers or glides which may be obtained in a multitude ofshapes, sizes, and load-bearing capacities. The pad 30 may be made ofany suitable material for the intended application such as plastic,metal, or a combination thereof, and may further include a non-slipmaterial such as rubber disposed on the underside surface of the padwhich contacts the floor. Although a round pad 30 is preferred, the padmay be any shape such as square, octagonal, etc.

[0099] In one embodiment shown in FIG. 5A, the end of the shaft 21 isconfigured with a concave head 22 and hex-shaped flange 39 to form partof a ball and socket type swivel joint for the pad 30. The concave head22 mates with a convex socket (not shown) provided in the pad 30. Anaxially aligned threaded recess 23 is shown which extends completelythrough the head 22 and flange 39, and partially into the elevationshaft 21. The recess 23 is intended to receive a threaded fastener (notshown) which may be used to secure the pad 30 to the shaft 21. The hexflange 39 allows a tool to be applied for holding the shaft 21 whileinstalling the pad 30. As is typical with swivel glides, the pad 30 isdesigned to freely rotate relative to the shaft 21. In addition, the pad30 swivels or tilts at an angle relative to a plane perpendicular to thelongitudinal axis of the shaft 21 to compensate for irregularities inflooring surfaces. Preferably, the pad 30 tilts at angle from 0 to about5 degrees; however, other ranges of angular movement may be used as amatter of design choice and the invention is not limited in this regard.Although a swivel type arrangement is preferred, a non-swiveling pad 30may also be used.

[0100] It will be appreciated that there are numerous possible ways ofconnecting a surface protector to the elevation shaft 21, the matterbeing strictly one of design choice. For example, some commerciallyavailable swivel glides have pads 30 that include a ball and socket witha female threaded hex coupling, thereby only requiring the elevationshaft 21 to have a simple threaded end that is screwed into the pad.Accordingly, the end configuration of the elevation shaft 21 is notlimited to the embodiments described herein. Moreover, although asurface protecting means is preferably disposed on the end of theelevation shaft 21, it is not necessary for the proper functioning ofthe leveling device 1 and may be omitted entirely.

[0101] The retaining collar 28 which may be used to hold the driven gear14 in the housing 2 is shown in FIGS. 6A & B. Preferably, the collar 28is circular in shape with at least one hole 29 disposed therein that maybe used to affix the collar to the housing 2. Preferably, two holes 29are used and the holes are threaded. The holes 29 align with holes 10(FIGS. 2A & B) also preferably threaded and provided in the housing 2.Set screws 80 (FIG. 1B) or similar means may be used to secure thecollar 28 in the housing 2. The thickness “t” of the collar need only belarge enough so that the inside diameter of the collar is slightlysmaller than the outside diameter of the driven gear 14, therebypreventing the driven gear from falling out of the housing 2. It shouldbe noted that when the leveling device 1 is installed in an object asshown in FIGS. 1B and 9 which shall be referred to herein as the“normal” vertical orientation or position, the collar 28 does not bearany of the weight of the object and only serves to hold the driven gearin the housing. Therefore, the collar 28 need not have high structuralstrength or rigidity when used in this manner.

[0102] In one embodiment, the inside diameter of the retaining collar 28and the outside diameter of the pad 30 are each cooperatively sized suchthat the pad may be completely withdrawn into the housing 2 of theleveling device 1 (see FIG. 1B, directional arrows above shaft 21). Thiscan be advantageous when shipping and installing an object to which theleveling device 1 is attached, such as an appliance for example. Theappliance, with pads 30 completely retracted into the housing 2, can beshipped and moved into its final installation position before theelevation shaft 21 and pads 30 are deployed. This eliminates the risk ofpotentially damaging the elevation shaft 21 and pad 30 while theappliance is in transit or being installed. Morever, depending on theamount that the base portion 3 is allowed to project from the undersideof the object 43 as shown in FIG. 9, the leveling device 1 (with the pad30 retracted into the housing 2) may be used as a slide to facilitatepushing the object into its final position. Also, if the base portion 3is made of plastic, the flooring surface is protected against scratchingand marring when the object is slid into position.

[0103] If the leveling device 1 is installed on the bottom of an objectin what shall be referred to as the “inverted” vertical position (FIG.10), whereby the device is vertically inverted 180 degrees from thenormal vertical orientation, the retaining collar 28 would be subjectedto loads imposed by the weight of the object (described in detailbelow). In this case, a load-bearing retainer with greater structuralstrength and a stronger method of attaching it to the housing 2 would berequired than with the collar 28 shown in FIGS. 6A & B. Accordingly, aload-bearing driven gear retainer 40 as shown in FIGS. 7A & B may beused in lieu of the collar 28. Preferably, the load-bearing retainer 40is a round, flattened structure, such as a solid circular disk, with ahole 42 disposed therein which is adapted and configured to receive theelevation shaft 21. The load bearing retainer 40 is not limited to thispreferred embodiment and any other suitable structure with load-bearingcapacity may be used for the retainer 40. The load-bearing retainer 40may be attached to the housing 2 of the leveling device 1 with setscrews 80 like the collar 28 as described above. However, the number ofset screws 80 and/or their size may be increased to provide a strongermeans of attaching the retainer 40 to the housing 2 as will be readilydeterminable using design and fabrication practices commonly known inthe art. Alternatively, any other suitable means may be used to attachthe retainer 40 to the housing 2 and the invention is not limited to theuse of set screws 80. For example, a threaded coupling could be usedbetween the retainer 40 and housing 2 by providing external threads onthe outer surface of the retainer 40 and internal threads in the hollowportion 4 and base portion hole 31 of the housing (FIG. 2A).

[0104] It is important to recognize that the load-bearing retainer 40need not be designed to solely withstand the loads imposed on theleveling device 1 by the weight of the object to which it is attached.It will be recalled that when the leveling device 1 is installed in the“inverted” vertical orientation and a load-bearing retainer 40 is used,the retainer actually lies next to the underside of object.Advantageously, the bottom frame or cabinet of the object, which by wayof example may be a copying machine, large frame computer, or otherbusiness machine, can be designed to bear the majority of the weightload imposed by the machine. This can be accomplished by ensuring thatthe load-bearing retainer 40 is braced against the bottom of themachine, thereby transferring the vertical weight load through theretainer to the underside of the machine. Under these circumstances,therefore, the load-bearing retainer 40 need only have sufficientstructural strength to transfer the weight load to the machine frame orcabinet. This will be more clearly understood from the followingdiscussion of the loads and forces imposed by an object on the levelingdevice 1.

[0105] The leveling device 1 is capable of handling both static anddynamic loads imposed by the object to which it is attached. Aspreviously mentioned, the stepped transition 32 (defined by the upperhorizontal surface 70 of the first internal compartment 5 and side wall71 of the second internal compartment 6 shown in FIG. 2B) and/or upperhorizontal surface 73 function with the driven gear 14 and/or stem 16(FIGS. 3A-D) to resist static and dynamic loads. The static loadcomprises the weight of the object which acts in a vertical planeparallel to the force of gravity. Dynamic loads are typically generatedby the motion of internal moving parts in the object and/or by externalforces imparted to the object. Examples of dynamic load sources causedby internal moving parts are vibrations and forces caused by washingmachine agitators, rotating drums in dryers, etc. An example of thedynamic load sources caused by external forces would be a person orequipment bumping into the object. Dynamic loads may act in both avertical and horizontal plane.

[0106] As best explained by reference to FIGS. 2B & 9, the static weightload of the object 43 and any vertical dynamic loads are transferred bythe upper horizontal surface 70 of the first compartment 5 to the upperflat surface 62 of the driven gear 14 which preferably contact eachother. The driven gear 14 transfers the static load to the elevationshaft 21 via the threaded connection provided between these twocomponents as described above. The static load is finally transferred bythe shaft 21 to the floor on which the object 43 rests. Thus, the upperhorizontal surface 70 eliminates the need for any separate bearings(e.g., thrust bearings, roller bearings, journal bearings, etc.) towithstand the vertical loads imposed by the object on the levelingdevice 1.

[0107] It should be recognized that the free end 65 (best seen in FIGS.3A & C) of the driven gear stem 16 may optionally be designed to contactthe upper horizontal surface 73 of the second internal compartment 6 inorder to transfer part or all of the vertical load (static and dynamic)through the stem to the upper flat surface 62 of the driven gear 14.This load is then transferred to the elevation shaft 21 and floor asdescribed above through the threaded connection between the shaft anddriven gear 14. Accordingly, all of the vertical loads may be designedto be transferred only to the stem 16, or the vertical loads may betransferred partially to both the upper horizontal surface 70 of thedriven gear 14 and the stem. As explained above, all of the verticalloads may be designed to be transferred to the upper flat surface 62 ofthe driven gear 14 alone.

[0108] With additional reference to FIG. 2B, any horizontal dynamicloads are transferred by the side wall 74 of the first internalcompartment 5 to the sides 64 and teeth 15 of the driven gear 14.Alternatively, if a driven gear 14 with one gear stem 16 is used asshown in FIG. 1B, the side wall 71 of the second internal compartment 6(FIG. 2B) may be designed to make contact with the stem and transferpart or all of the horizontal dynamic loads to the stem. In this case,all of the horizontal dynamic loads may be designed to be transferredonly to the stem 16, or the dynamic loads may be transferred partiallyto both the sides 64 and teeth 15 of the driven gear 14 and the stem. Ifmore than one gear stem 16 is used in the leveling device 1 (FIG. 3E),part or all of the horizontal dynamic loads may also be transferred tothe additional gear stem similarly to that just described for a singlestem above. As explained above, all of the horizontal loads may bedesigned to be transferred to the side wall 74 of the first internalcompartment 5 alone. Thus, the side walls of the first and secondinternal compartments 5 and 6, respectively, eliminate the need for anyseparate bearings (e.g., thrust bearings, roller bearings, journalbearings, etc.) to withstand the horizontal dynamic loads that may beimposed by the object on the leveling device 1.

[0109] It will be appreciated that the upper horizontal surface 70 ofthe first compartment 5 and the upper flat surface 62 of the driven gear14 should have a reasonably smooth surface finish to allow the drivengear to be rotated without binding under the static weight of the objectto which the leveling device 1 is attached. Since it is unlikely thatthe object will be operated or bumped while it is being leveled, theleveling device 1 need not be designed to allow the driven gear 14 to berotated under any vertical dynamic loads.

[0110] Operation of the leveling device 1 will now be described withgeneral reference to FIGS. 9 & 11. In FIG. 9, the leveling device 1 isshown mounted to the underside of an object 43 in the “normal” verticalorientation with the base portion 3 at the bottom and the top portion 13at the top. The substantially hollow portion 4 and top portion 13 of thehousing project upwards inside the object 43. Although the bottom of thebase portion 3 is shown as being mounted substantially flush with theunderside of the object 43 (in a depression provided therein which isadapted and configured to mate with the shape of the base portion), theleveling device may also be surface mounted such that the full height ofbase portion projects completely below the underside of the object (notshown). It will be appreciated that the leveling device 1 may be mountedto the object 43 with any portion of the base portion 3 projecting belowthe underside of the object, or none at all.

[0111] Mounting screw 49 is shown (FIG. 9) which attaches the levelingdevice 1 to the underside of the object 43 through holes 11 in the baseportion 3. Although a countersunk bolt and mating hole are depicted, itwill be appreciated that any type or shape of bolt or screw may be usedto attach the leveling device 1 to the object 43 which is matter ofdesign choice (see, e.g., FIG. 10 depicting use of hex head bolts). Inthe installation shown in FIG. 9, countersunk bolts or screws arepreferred to avoid scratching or marring the flooring surface while theobject 43 is slid into its final position by the installers. It shouldalso be recognized that conventional hex head bolts (FIG. 10) may alsobe countersunk by providing a shallow depression in base portion 3surrounding the hole 11 such that the bolt head lies at or below thebottom surface of the base portion.

[0112] Preferably as shown in FIG. 11, at least two leveling devices 1may be installed near each rear comer of the object 43 to serve as therear supports. However, it will be readily appreciated that the levelingdevice 1 may be used with all supports that may be provided for theobject 43, the number of leveling devices being a matter of designchoice dependent on the size and weight of object. The extension rods 36are shown in FIG. 11 as reaching from the leveling devices 1 to thefront of the object where they are readily accessible by installers withtools.

[0113] Operation of the leveling device 1 will be described for anembodiment in which an object has two leveling devices, one eachinstalled near the two rear corners of the object. After the object 43is moved into its final position on a floor, it is ready to be leveledusing the leveling devices 1. For this example, it is assumed that thepad 30 of each leveling device 1 is completely retracted into thehousing 2 as described above and which is the preferred pre-levelingposition of the pads. The installer applies a tool to the tooling end 38of one leveling device's extension rod 36 and begins to rotate theextension rod in a predetermined direction that will lower the elevationshaft 21 toward the floor. This in turn rotates the worm gear 25 in thehousing 2 of the leveling device 1 which is operably engaged with theteeth of the driven gear 14, whereupon concomitant rotations of thedriven gear lowers the elevation shaft 21. As the shaft 21 is lowered,the pad first emerges from the housing 2 and engages the flooringsurface. Continued rotation of the extension rod 36 in the samedirection by the installer causes the object to then be raised or liftedoff the flooring surface. The installer continues to raise the object 43until the desired height is reached. It should be recognized that theinstaller may also lower the height of the object by reversing thedirection in which the extension rod 36 was initially being rotated.After adjustments to the first leveling device 1 are completed, thissame process is then repeated for the remaining leveling device. It willbe apparent that the installer may make gradual adjustments to theheight of each comer of the object 43, going back and forth betweenleveling devices 1, until the proper overall height of the object isreached and it is level. If an object 43 were provided which had morethan two leveling devices 1 as just described (not shown), the sameleveling procedure would be repeated for each leveling device.

[0114] It will be appreciated that the direction in which the installermust rotate the extension rod 36 to raise or lower the object 43 isdependent upon whether a worm gear with righthanded or left-handedthreads is installed in the leveling device 1, and the horizontalorientation of the leveling device as installed in the object. In FIG.11, for example, one rear comer leveling device 1 is shown as beinginstalled in a position that has been horizontally turned 180 degreesfrom the other rear comer leveling device. This is desirable so that theelevation shaft 21 of each leveling device 1 which supports the weightof the object 43 are each equidistant from both rear corners of theobject. Since it is preferable for an installer to be able to turn bothextension rods 36 in the same direction to either raise or lower theobject 43, a right-handed worm gear 25 may be used in one rear levelingdevice 1 while a left-handed worm gear may be used in the other. Thisavoids inconvenience to the installers and confusion.

[0115] In another embodiment shown in FIG. 10, the leveling device 1 isinstalled vertically inverted by 180 degrees from its normalorientation. When installed in an object 43 in the inverted position,the base portion 3 is at the top and the top portion 13 is at thebottom. Accordingly as shown, the full height of the housing projectsdownwards from the underside of the object 43. This is desirable in anumber of applications, including, but not limited to large businessmachines (e.g., copiers, computers, sorters, etc.) and industrialequipment which may be fitted with both conventional fixed-heightrollers (not shown in FIG. 10) and height-adjustable supports with pads.The rollers are used to make moving these often heavy objects 43 intoplace easier for installers. After the object 43 is rolled into itsfinal position, the height-adjustable supports such as the levelingdevice 1 of the invention as depicted in FIG. 10 are used to slightlyraise the object off the rollers (to prevent subsequent rolling of themachine) and level the object. It is therefore desirable to minimize thelength of the elevation shaft 21 which would otherwise be long if theleveling device 1 were flush mounted to the underside of the object 43in its normal orientation. It will be readily appreciated that theleveling device 1 may be installed in the inverted position and usedalone without any concurrent use of rollers.

[0116]FIG. 10 also shows conventional hex head bolts 50 that may beinserted through hole 11 in the base portion 3 of the leveling device 1to attach the leveling device to the object 43. As discussed above inreference to FIG. 9, any type or shape of bolt or screw may be used inconjunction with hole 11 for attaching the leveling device 1.

[0117] It should be recognized that a commercially available lubricantsuch as grease or oil may be applied to the teeth of the driven gear 14and worm gear 25 to facilitate smooth operation of the leveling device1. Lubricant may also applied to the upper flat surface of the drivengear 14 where it contacts the stepped transition 32 of the housing 2,and to the surfaces of any gear stems 16 if used to facilitate theirrotation in the housing while under the loads described above (referenceFIGS. 1B & 2B). Alternatively, a washer partially or fully coated with anon-stick, low friction polymeric material such as PTFE, FEP, PFA, ETFE,etc. may also be disposed between the upper surface of the driven gear14 and the stepped transition 32, and between the free end of gear stem16 and the top of the second internal compartment to facilitate rotationof driven gear and stem. Optionally, the non-stick material may becoated on the driven gear 14 and/or internal compartments 5 and 6instead of, or in addition to, using non-stick washers. Although the useof lubricants and non-stick materials are described above, the levelingdevice 1 may be used without any of these.

[0118] It will be appreciated that the leveling device is not limited bythe location where they may be mounted on the underside of an object.Although placement of the leveling device is preferably near the cornersof an object, placement is a design choice and the invention is notlimited to embodiments described herein having leveling devices mountednear the corners. In certain applications, and depending on theconfiguration and size of the object, it may be desirable to place theleveling devices at locations other than near the corners, or atadditional locations besides near the corners.

[0119] It should be recognized that the leveling device 1 and itscomponents are not limited by the type of material from which they maybe constructed. Accordingly, plastics, plated or unplated metals andalloys, molded fiberglass, composites, press fitted combinations, etc.may be used alone or in combination for each component, the selectionbeing a matter of design choice and requirements of the particularintended application.

[0120] The invention has broad applicability for use in many types ofobjects that require leveling and is not limited to the embodimentsdescribed herein. Thus, for example, the leveling device 1 can be usedalone or in combination with conventional levelers in appliances,industrial machinery and equipment, office and business machines such ascopiers, mail sorters, etc., electronic and computer equipment, medicaland dental equipment, telecommunications equipment, recreationalequipment, furniture, and others.

[0121] It will be recognized by those skilled in the art that thedetails of the leveling device described herein are a matter of designchoice, and the invention is not limited to the particular embodimentsand features described. Accordingly, numerous modifications may be madeto the leveling device and its components without departing from thespirit of the invention and scope of the claims appended hereto.

What is claimed is:
 1. A leveling device consisting of: (a) a housinghaving a base portion, a top portion, and a substantially hollowportion, the hollow portion adapted and configured to provide at leastone load-bearing surface; (b) an elevation shaft having a longitudinalaxis disposed at least partially within the hollow portion, at least aportion of the shaft having threads on its external surface; (c) a wormgear having teeth disposed within the housing, at least one end of theworm gear having an extension protruding out from the housing andconfigured to facilitate rotation of the worm gear; (d) a driven geardisposed within the hollow portion having internal threads engaged withthe threads of the elevation shaft and external gear teeth engaged withthe teeth of the worm gear, the driven gear adapted and configured tooperably engage the at least one loadbearing surface without anyseparate bearings; (e) means for retaining the driven gear within thehollow portion; and (f) means for restraining the elevation shaft fromrotating relative to the housing, whereby upon rotation of the worm gearin opposite directions and concomitant rotations of the driven gear, theelevation shaft is caused to move axially up or down to provide levelingmotions to an object attached to the device.
 2. The leveling device ofclaim 1 wherein the driven gear is a spur gear.
 3. The leveling deviceof claim 1 wherein the driven gear has a stem with a longitudinalcenterline.
 4. The leveling device of claim 1 wherein the driven gear isa helical gear.
 5. The leveling device of claim 1 wherein the means forretaining the driven gear within the substantially hollow portion is acollar fastened within an opening in the base portion.
 6. The levelingdevice of claim 1 wherein the means for retaining the driven gear withinthe hollow portion is a load-bearing block fastened within an opening inthe base portion, the block having a hole configured and adapted toreceive the elevation shaft.
 7. The leveling device of claim 1 whereinthe elevation shaft is axially movable to completely retract at leastone end of the shaft into the housing.
 8. The leveling device of claim 1wherein the extension of the at least one end of the worm gearprotruding out from the housing is configured as a hex head.
 9. Theleveling device of claim 1 wherein the means for restraining theelevation shaft from rotating relative to the housing comprises anopening disposed in the top portion of the housing through which theelevation shaft extends, the opening having a flat surface, and a flatportion configured on the shaft to operably engage the flat surface inthe opening to prevent rotation of the shaft.
 10. The leveling device ofclaim 1 wherein the means for restraining the elevation shaft fromrotating relative to the housing comprises a slot extending along aportion of the longitudinal axis of the elevation shaft, an openingdisposed in the top portion of the housing through which the elevationshaft extends, and the opening having a key to operably engage the slotto prevent rotation of the shaft.
 11. The leveling device of claim 1wherein the means for restraining the elevation shaft from rotatingrelative to the housing comprises a key extending along a portion of thelongitudinal axis of the elevation shaft, an opening disposed in the topportion of the housing through which the elevation shaft extends, andthe opening having a slot to operably engage the key to prevent rotationof the shaft.
 12. The leveling device of claim 1 wherein the worm gearis made of plastic.
 13. The leveling device of claim 1 wherein thedriven gear is made of plastic.
 14. The leveling device of claim 1wherein the housing is made of plastic.
 15. A device for leveling anobject consisting of: (a) a housing having a base portion, a topportion, and a substantially hollow portion, the hollow portion adaptedand configured to provide at least one load-bearing surface; (b) anelevation shaft having a longitudinal axis disposed at least partiallywithin the hollow portion, at least a portion of the shaft havingthreads on its external surface; (c) means connected to one end of theelevation shaft for protecting a nonuniform surface from damage bycontact of the end with the nonuniform surface; (d) a worm gear havingteeth disposed within the housing, at least one end of the worm gearhaving an extension protruding out from the housing and configured tofacilitate rotation of the worm gear; (e) a driven gear disposed withinthe hollow portion having internal threads engaged with the threads ofthe elevation shaft and external gear teeth engaged with the teeth ofthe worm gear, the driven gear adapted and configured to operably engagethe at least one load-bearing surface without any separate bearings; (f)means for retaining the driven gear within the hollow portion; and (g)means for restraining the elevation shaft from rotating relative to thehousing, whereby upon rotation of the worm gear in opposite directionsand concomitant rotations of the driven gear, the elevation shaft iscaused to move axially up or down to provide leveling motions to anobject attached to the device.
 16. The leveling device of claim 15wherein the surface protecting means comprises a pad shaped as a rounddisk.
 17. The leveling device of claim 16 wherein the elevation shaft isaxially movable such that the pad may be completely retracted into thehousing.
 18. The leveling device of claim 16 wherein the pad is rotablyconnected to the end of the elevation shaft to permit independentrelative rotation between the pad and the shaft.
 19. The leveling deviceof claim 16 wherein the pad is movably attached to the end of theelevation shaft to permit the pad to tilt at an angle relative to aplane perpendicular to the longitudinal axis of the elevation shaft. 20.The leveling device of claim 19 wherein the angle ranges from 0 to about5 degrees.
 21. The leveling device of claim 15 wherein the surfaceprotecting means comprises a roller.
 22. The leveling device of claim 21wherein the roller is pivotally mounted to the end of the elevationshaft to permit swiveling of the roller around the elevation shaft. 23.A device for leveling an object comprising: (a) a housing adapted andconfigured to attach to the object, the housing having a base portion, atop portion, and a substantially hollow portion, the top portion beingsituated opposite the base portion, each such portion having at leastone opening, the hollow portion having a first internal compartment witha first cross-sectional area parallel to the base portion and a secondinternal compartment with a second cross-sectional area parallel to thebase portion, the second cross-sectional area being smaller than thefirst cross-sectional area, the first internal compartment communicatingwith the second internal compartment and the at least one opening in thebase portion, the second internal compartment communicating with the atleast one opening in the top portion, and a stepped transition betweenthe first internal compartment and the second internal compartmentadapted and configured to define at least one load-bearing surface; (b)an elevation shaft having a longitudinal axis disposed at leastpartially within the hollow portion, at least a portion of the shafthaving threads on its external surface; (c) a worm gear having teethdisposed within the housing, at least one end of the worm gear having anextension protruding out from the housing and configured to receive atool to facilitate rotation of the worm gear; (e) a driven gear disposedin the first internal compartment having internal threads engaged withthe threads of the elevation shaft and external gear teeth engaged withthe teeth of the worm gear, the driven gear having a top and a bottomwherein the top of the driven gear contacts the load-bearing surface ofthe stepped transition without any separate bearings; (f) a stem havinga longitudinal centerline extending from the top of the driven gear andbeing disposed in the second internal compartment, the stem having apassageway oriented through its longitudinal centerline configured andadapted to receive the elevation shaft; (g) means for retaining thedriven gear within the hollow portion; and (h) means for restraining theelevation shaft from rotating relative to the housing, whereby uponrotation of the worm gear in opposite directions and concomitantrotations of the driven gear, the elevation shaft is caused to moveaxially up or down to impart leveling motions to the object.
 24. Amethod for leveling an object comprising: (a) providing at least twoleveling devices each comprising: a housing having a base portion, a topportion, and a substantially hollow portion; an elevation shaft having alongitudinal axis disposed at least partially within the hollow portion,at least a portion of the shaft having threads on its external surface;a worm gear having teeth disposed within the housing, at least one endof the worm gear having an extension protruding out from the housing andconfigured to receive a tool to facilitate rotation of the worm gear; adriven gear disposed within the hollow portion having internal threadsengaged with the threads of the elevation shaft and external gear teethengaged with the teeth of the worm gear; means for retaining the drivengear within the hollow portion; and means for restraining the elevationshaft from rotating relative to the housing, whereby upon rotation ofthe worm gear in opposite directions and concomitant rotations of thedriven gear, the elevation shaft is caused to move axially up or down;(b) providing a tool configured to operably engage the at least one endof the worm gear extending out from the housing; (c) providing an objectto which the at least two leveling devices are mounted, the objectproviding access for the tool to engage the at least two levelingdevices; (d) engaging the tool with the extension of the at least oneend of the worm gear protruding out from the housing of one of the atleast two leveling devices; and (e) rotating the worm gear of one of theat least two leveling devices with the tool to raise or lower theobject.
 25. The method of claim 24 wherein the object is an appliance.26. The method of claim 24 wherein the object is leveled by rotation ofthe worm gear of at least one of the leveling devices.
 27. The method ofclaim 24 wherein the object is leveled by rotation of both worm gears ofthe at least two leveling devices.
 28. A housing for a leveling devicecomprising: (a) a base portion having an opening; (b) a top portionhaving an opening; and (c) a hollow portion between the top and baseportions, the hollow portion defining a gear cavity having a firstcross-sectional area parallel to the base portion, the gear cavitycommunicating with the opening in the base portion, the hollow portionfurther defining a gear stem cavity having a second cross-sectional areaparallel to the base portion and which is smaller than thecross-sectional area of the gear cavity, the gear stem cavitycommunicating with and disposed above the gear cavity, the gear stemcavity communicating with the opening in the top portion wherein thegear cavity is coaxially aligned with the gear stem cavity and a steppedtransition is formed between the gear cavity and the gear stem cavity,the stepped transition providing a load-bearing surface.
 29. The housingof claim 28 further comprising a substantially rectangular worm gearcavity communicating with the gear cavity, the worm gear cavity havingan open top, a closed bottom, two elongated sides, and two ends with anopening disposed in each end.
 30. The housing of claim 29 wherein theshape of the closed bottom is semi-circular.
 31. The housing of claim 29wherein the housing is fabricated by machining.
 32. The housing of claim29 wherein the housing is plastic.
 33. The housing of claim 32 whereinthe housing is fabricated by molding.
 34. A device for leveling anobject comprising: (a) a housing having a base portion and a top portionand including a substantially hollow portion, the top portion situatedopposite the base portion, and the top portion and the base portion eachhaving at least one opening, such housing adapted and configured toattach to the object in an inverted position whereby the base portion isoriented upwardly and the top portion is oriented downwardly; (b) anelevation shaft having a longitudinal axis disposed at least partiallywithin the hollow portion and extending out the at least one opening inthe top portion, at least a portion of the shaft having threads on itsexternal surface; (c) a worm gear having teeth disposed within thehousing, at least one end of the worm gear having an extensionprotruding out from the housing and configured to receive a tool tofacilitate rotation of the worm gear; (e) a driven gear disposed in thehollow portion having internal threads engaged with the threads of theelevation shaft and external gear teeth engaged with the teeth of theworm gear; (f) a load-bearing block inserted within the at least oneopening in the base portion, the block having a hole configured andadapted to receive the elevation shaft, thereby providing a load-bearingsurface for support of the load imposed on the leveling device by theobject; and (g) means for restraining the elevation shaft from rotatingrelative to the housing, whereby upon rotation of the worm gear inopposite directions and concomitant rotations of the driven gear, theelevation shaft is caused to move axially up or down to impart levelingmotions to the object.